\section{Introduction}
\label{sec:introduction}
For many years the only way to stream media data from online sources have been with a client-server structure. When internet connectivity was limited to a relatively small percentage of people, this was not a problem, but recent years explosion in personal computers and the size of the average persons bandwidth, has posed some interesting difficulties in managing the huge load some media streaming websites are experiencing. Just taking a look at a site like Youtube.com easily gives you an idea about the quantity of servers and bandwidth necessary to supply the demand of media in a reasonable amount of time. Since servers and bandwidth are still a non-negligible expense, it is worthwhile researching new ways to supply video-on-demand (VoD).

One such possibility lies in utilizing Peer-to-Peer (P2P) technology to lessen the load of the servers. The last couple of years have seen a small explosion in the research of using P2P, and particularly the BitTorrent protocol to revolutionize the VoD streaming industry.

In this report we explore two different strategies for modifying the BitTorrent protocol to suit our purpose. Both strategies involve a change in the BitTorrent piece selection policy which will be described in section \ref{sec:bittorrent}. We implement the two strategies in an existing BitTorrent client, and evaluate our results. We then compare the two strategies and make a conclusion based on the evaluation and our assessment on the possibilities for future work.
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As hinted a bit earlier, the motivation for this kind of system is very palpable, and with the strategies proposed in our report it should be possible to make VoD streaming a less expensive industry. As a bonus, you should be able to download regular media files using the common BitTorrent trackers, and start watching or listening to it before the download completes.
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Our report is build up like so: Section \ref{sec:related_work} describes related work in the field. In section \ref{sec:system_description} we describe the BitTorrent piece selection policy and our changes to it. Those changes are then evaluated in section \ref{sec:evaluation}. We then conclude on our results in section \ref{sec:conclusion}, and finally we describe some possibilities for future work in the field in section \ref{sec:future_work}.

\begin{comment}
Some introductory text describing the problems and challenges within the field.  Why is your system interesting?
\end{comment} 